Do you know the typical signs of labor? Understand the changes your body will go through as you prepare to give birth.
By Mayo Clinic Staff

On television, babies are often born with a rush of emotion and swift action. The mother doubles over from the pain of a single contraction, and the baby appears before the commercial break. In reality, however, labor usually begins less dramatically. Find out common signs of labor and what they mean for you and your baby.

One of the first signs of labor is your cervix softening and thinning, or effacing. Most of the effacing happens in the last weeks before delivery, and you won't feel this preparation happening. Instead, your health care provider might check for signs of cervical change with vaginal exams.

Effacement is often expressed in percentages. At 0 percent effacement, the cervix is typically about 3 to 4 centimeters (cm) long, or very thick. Your cervix must be 100 percent effaced, or completely thinned out, before a vaginal delivery.

Another of the early signs of labor is your cervix beginning to open (dilate). Your health care provider will measure the dilation in centimeters from zero to 10.

At first, these cervical changes can be very slow. Once you're in active labor, expect to dilate more quickly.

Light spotting between weeks 37 and 40 of pregnancy could be a sign that labor is starting. Vaginal discharge that is pink or bloody is known as the bloody show. If vaginal bleeding is as heavy as a normal menstrual period, however, contact your health care provider immediately. Heavy vaginal bleeding could be a sign of a problem.

During pregnancy, a thick plug of mucus blocks the cervical opening to prevent bacteria from entering the uterus. When your cervix begins to thin and open, this plug might fall out. Losing the mucous plug is among the telltale signs of labor, but it's not a guarantee. Labor might still be days or weeks away.

You might wake up one morning feeling energetic, eager to fill the freezer with prepared meals, set up the crib and arrange your baby's outfits according to color. This urge is commonly known as nesting. No one knows for sure, but it could be a primal instinct that hearkens back to a time when physical preparation was necessary for a safer childbirth.

Nesting might begin months before your due date, but the instinct is usually strongest just before delivery. Do what you must, but don't wear yourself out. Save your energy for the harder work of labor ahead.

The amniotic sac is a fluid-filled membrane that cushions your baby in the uterus. At the beginning of or during labor, your membranes will rupture — also known as your water breaking.

When your water breaks you might experience an intermittent or continuous trickle of small amounts of watery fluid from your vagina or a more obvious gush.

If your water breaks — or if you're uncertain whether the fluid is amniotic fluid, urine or something else — consult your health care provider or head to your delivery facility right away. You and your baby will be evaluated to determine the next steps.

If the amniotic sac is no longer intact, timing becomes important. The longer it takes for labor to start after your water breaks, the greater your or your baby's risk of developing an infection. Your health care provider might stimulate uterine contractions before labor begins on its own (labor induction). In the meantime, avoid doing anything that could introduce bacteria into your vagina, such as having sex.

During the last few months of pregnancy, you might experience occasional, sometimes painful, contractions — a sensation that your uterus is tightening and relaxing. These are called Braxton Hicks contractions. They're your body's way of warming up for labor.

To tell the difference between Braxton Hicks contractions and the real thing, consider these questions:

Are the contractions regular? Time your contractions from the beginning of one to the beginning of the next. Look for a regular pattern of contractions that get progressively stronger and closer together. False labor contractions will remain irregular.

How long do they last? Time how long each contraction lasts. True contractions last 30 to 90 seconds.

Do the contractions stop? True contractions continue regardless of your activity level or position. With false labor, the contractions might stop when you walk, rest or change position.

Remember, no one knows for sure what triggers labor, and every woman's experience is unique. Sometimes it's hard to tell when labor begins.

Don't hesitate to call your health care provider if you're confused about whether you're in labor. Preterm labor can be especially sneaky. If you have any signs of labor before 36 weeks — especially if you also experience vaginal spotting — consult your health care provider.

At term, labor will nearly always make itself apparent. If you arrive at the hospital in false labor, don't feel embarrassed or frustrated. Think of it as a practice run. The real thing is sure to be on its way!

Frequently asked questions. Labor, delivery, and postpartum care FAQ004. How to tell when labor begins. American College of Obstetricians and Gynecologists. http://www.acog.org/~/media/For%20Patients/faq004.pdf?dmc=1&ts=20130319T1126253346. Accessed March 19, 2013.

Herbst A, et al. Time between membrane rupture and delivery and septicemia in term neonates. Obstetrics & Gynecology. 2007;110:612.

You and your baby: Prenatal Care, Labor and Delivery, and Postpartum Care. Washington, D.C.: American College of Obstetricians and Gynecologists; 2011:1.

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